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Tulsa University Separation Technology Projects (TUSTP)

2011 Questionnaire

Please complete pages 1 & 2 and return to:

Judy TealProject Coordinator, TUSTPMcDougall School of Petroleum Engineering The University of Tulsa800 South Tucker DriveTulsa, OK, 74104-3189, USAEmail: [email protected].: 918-631-2048Fax: 918-631-2059

Representative and Company Names:

The following table contains titles of recently completed (2010), ongoing or proposed future projects for TUSTP and the related projects sponsored by Tulsa University/Chevron Center of Research Excellence (TU-CoRE) and the National Science Foundation Industry/University Cooperative Research Center (NSF-I/UCRC). A brief description of each project is given in the pages following the table.

Please provide your name (plus the name of your company) and indicate your level of interest in each project to help us guide future TUSTP research. (Double click on the preferred check box and a dialog box will appear, namely, “Check Box Form Field Options”. In this dialog box, click the “Check” radio button for the “Default value”). Your input is very important to us. This will help TUSTP faculty to make the final decision on project activities based on membership preference, timing, budget and availability of students and facility resources.

We thank you very much for your time and cooperation.

TUSTP 2011 Questionnaire 1 April 2011

mailto:[email protected]

TUSTP Questionnaire 2011Representative and Company Names:

No. Research Project Titles StatusLevel of Interest

Very High

High Med Low None

Recently Completed Projects (2010) (1-6)

1 Modeling of Integrated Compact Multiphase Separation System (CMSS©) TUSTP

2Modeling and Applications of Differential Dielectric Sensor (DDS) for Multiphase Measurement

TU-CoRE / TUSTP

3 Validation and Improvement of the Horizontal Pipe Separator (HPS©) Model

Saudi Aramco / TUSTP

4Onset to Separated Water-Layer in Three-Phase Stratified Flow TU-CoRE

5Shear Effects of Centrifugal Pump on Hydrocyclone Performance TU-CoRE

6Methodology of Oil-Water Dispersions Flow Characterization Using the Dispersion Characterization Rig (DCR)

TU-CoRE

Ongoing Projects (7-18)

7 Falling Film and Gas Entrainment in a Tall GLCC© TUSTP

8 Multiphase Flow in Downcomers TU-CoRE

9 Droplet Coalescence and Deposition in Curved Pipes

TU-CoRE/ I/UCRC

10 A Foam Breakup in Cyclones – Foam Characterization Rig (FCR) TU-CoRE

11 Gas Effect on Differential Dielectric Sensor (DDS) Measurements TUSTP

12 Fluid Shear Effects of Production Equipment TU-CoRE

13 Interfacial Phenomenon of Crude Oil & Water Dispersions using DCR TU-CoRE

14 Multiphase Flow Splitting in Looped Pipelines TU-CoRE

15 Simulation of Different Geometries of the Differential Dielectric Sensor (DDS©) TUSTP

16 Oil Chemistry in Emulsion Characterization TU-CoRE

17 High Pressure Entrainment Measurement and Modeling

TUSTP / SwRI

18 Sand Transport in Multiphase Pipelines TUSTP


Proposed Future Projects (19-28)19 Field Testing of LLCC© Future

20 Separation of Slurries in GLCC© Compact Separators Future

21 Platform to Platform Pipeline Flow Behavior Future

22 CFD Simulations of CMSS© Components Future

23 Operational Envelope for LCO in GLCC© – Experiments and Modeling Future

24 Gas Carry-Under in GLCC© – Experiments and Modeling Future

25 GLCC© Inlet Slot Optimization Future

26 GLCC© Liquid Outlet and Gas Outlet Optimization Future

27 Verification of GLCC© Performance with Real Fluids at High Pressure Future

28 A Review of GLCC© in Topsides and Subsea Processes Future


Recently Completed (2010), Ongoing and Possible Future Research Projects of

TUSTP, TU-CoRE and NSF-I/UCRC – April 2011

Recently Completed Projects (2010) (1-6)

1) Modeling of Integrated Compact Multiphase Separation System (CMSS©) (TUSTP)

A methodology for the performance prediction of integrated compact multiphase separation system (CMSS©) has been developed. The proposed methodology is based ontracking droplets and bubbles evolution throughout the system, enabling the prediction of the flow behavior through the system interconnections and process devices. Two approaches are proposed for predicting particle size evolution in the integrated system, namely the steady-state approach and the discrete formulation approach. The proposed steady-state particle size approach is simple, practical and computationally efficient. For the first time, the discrete formulation approach is utilized to solve the integrated system, including process devices, pipe sections, fittings and accessories. New models have been developed for the integrated CMSS©. These include particle (bubbles and droplets) size distribution predictions for steady-state conditions; model for particle evolution through the integrated CMSS©; inlet flow pattern dependent modeling upstream of the CMSS©, for predicting the amount of entrained phases and the respective particle size distributions; and, improved models for the GLCC©, HPS and conventional separators. Databases have been developed for particle size distributions, inlet flow characterization and separators performance. All the new models have been tested against the respective data bases showing a good agreement. All the developments presented in this study can be incorporated in any available process simulator, improving their accuracy due to inclusion of the physical phenomena occurring in processing facilities for multiphase flow.

2) Modeling and Applications of Differential Dielectric Sensor (DDS) for Multiphase Measurement (TU-CoRE/TUSTP)

Although several technologies for water cut measurement are available to provide solutions for the oil and gas industry, it is still necessary to improve the accuracy, to generalize applications and to reduce the cost of measurement. Predominantly, the existing water cut measurement technologies depend on empirical models or correlations which are labor intensive and time consuming. Also, frequent calibrations are usually required to compensate for the effects of temperature, salinity, oil density, emulsion status, and flow regimes. Droplet size, which greatly affects composition measurement, has not been compensated for in the existing technologies, resulting in significant uncertainties.

This research effort aims to employ an analytical approach to develop a measurement model for the use of Differential Dielectric Sensor (DDS) for water cut measurement. The analytical approach is believed to be superior to empirical models and correlations commonly used throughout the area of multiphase metering in reducing the cost of sensor optimization and overcome the need for frequent calibrations under field conditions. The DDS measurement model includes a dielectric mixture model which calculates the average dielectric permittivity of a


water/oil or oil/water mixture and sensor model which calculates attenuation and phase. The dielectric mixture model is developed in this study by introducing the scattering effects of microwave due to the suspended particles (droplet size effect) into Hanai dielectric mixture model (1960).

A comprehensive experimental program is conducted in order to investigate the effects of temperature, salinity and shear rate or droplet size. A lookup table approach associated with an appropriate searching algorithm is employed to convert differential attenuation and differential phase into water cut, droplet size and average dielectric permittivity simultaneously. A systematic uncertainty analysis is presented in this report that describes the factors contributing to the overall uncertainty of DDS technology.

3) Validation and Improvement of Horizontal Pipe Separator (HPS©) Model (Saudi Aramco/TUSTP)

A wide range of experimental data was acquired for oil-water mixture flow behavior, and the entry region required for the oil and water separation in the HPS©. A total of 34 runs were conducted for mixture velocities of 0.08, 0.13, 0.20 and 0.30 m/s with water cuts between 10 to 90%. The experimental data confirmed that the higher the mixture velocity, the longer the entry region required for separation. On the other hand, when increasing the water cut, the water separation is more efficient. Similarly, increasing the oil volume fraction results in an easier separation of the oil phase. The water cut has a stronger effect on the water separation than the oil volume fraction on the oil separation. For low water cuts (10 to 30%) and high mixture velocity (0.30 m/s), no separation between the phases was observed.

The Gassies (2008) model has been validated and improved for water continuous flow by developing correlations for two of the Gassies model’s input variables, namely, the turbulence decay time and the oil volume fraction in the dense packed zone. For the water-continuous flow cases (WC between 30 to 90%), a comparison between the improved model predictions and the experimental data show a very good agreement for the sedimenting interface. For low mixture velocities (0.08 and 0.13 m/s), good agreement is observed also for the coalescing interface. For the oil-continuous flow cases (WC= 10 and 20%), comparison between the improved model predictions and the experimental data also show a good agreement for the sedimenting interface. However, for this case no agreement was observed for the coalescing interface.

4) Onset to Separated Water-Layer in Three-Phase Stratified Flow (TU-CoRE)

The onset to separated water-layer in three-phase gas-oil-water stratified flow is studied theoretically and experimentally, aimed at the determination of the transition boundary between the separated liquid-phase and the dispersed liquid-phase. An experimental facility was constructed, enabling data acquisition under three-phase stratified flow. A total of 75 experimental runs were conducted for five superficial gas velocities between 0.3 and 6.1 m/s and three superficial liquid velocities, from 0.01 to 0.03 m/s. The water cut ranged between 5% and 40% for each superficial liquid velocity. The experimental transition boundary between the separated and dispersed liquid-phase was determined based on visual observations for all the runs. The results are presented in the form of flow pattern maps, including the transition boundary between the two liquid-phase flow configurations. For low superficial liquid velocities,


Separated-Liquid-Phase Stratified-Smooth flow occurs. Increasing the superficial gas velocity promotes transition to dispersed liquid-phase, for low water cuts. The transition mechanism is the occurrence of large waves at the oil-water interface. These waves reach the bottom of the pipe, swiping the water layer and dispersing it. The resulting flow pattern is Dispersed-Liquid-Phase Stratified-Wavy flow. A mechanistic model was developed for the prediction of the transition boundary between the separated and dispersed liquid-phase under three-phase stratified flow. The proposed model requires as input the three-phase stratified flow variables, which are determined based on the Taitel et al. (1994) model. The transition boundary is then predicted based on the proposed flow mechanism, utilizing a simple Froude number criterion. The model predictions show a good agreement with the acquired experimental data on the liquid-phase flow behavior. Uncertainty analysis shows a 7.3% average error for the water height and 18% average error for the oil height measurements.

5) Shear Effects of Centrifugal Pump on Hydrocyclone Performance (TU-CoRE)

The liquid-liquid hydrocyclone (LLHC) has been widely used for decades by the Petroleum Industry for oil-water separation. In many applications upstream boosting devices, such as centrifugal pumps, are used to provide the mixture with the required pressure to achieve effective separation. However, the pump shear may have a negative impact on the hydrocyclone performance, lowering its efficiency. In this study, an integrated pump-hydrocyclone system was studied experimentally and theoretically. Droplet size and oil concentration measurements have been carried out at the underflow stream of a 2 inch LLHC for different pump speeds. The experimental tests demonstrate a decrease of the droplet size distribution at the hydrocyclone underflow stream for the higher pump speeds, while the oil concentration increases owing to larger volume fractions associated with the resulting small droplets. Nevertheless, a good oil separation performance is observed, achieving efficiencies larger than 95%. The integrated centrifugal pump–hydrocyclone mechanistic model shows good agreement with the experimental data for the droplet size distribution, efficiency, and pressure drop predictions.

6) Methodology of Oil-Water Dispersions Flow Characterization Using the Dispersion Characterization Rig (DCR) (TU-CoRE)

An experimental study of the characterization of oil-water dispersions flow was carried out in the Dispersion Characterization Rig (DCR), a state-of-the-art facility, for studying the separation process of dispersions, in order to develop a methodology to characterize oil-water dispersions flow. In this study, experiments with two different types of water (distilled water, and a 3.5% w/w solution of sodium chloride and tap water) and three different oils (Crystex AF-L, Crystal 70FG, and a crude oil sample) are evaluated by means of the identification of the continuous phase and their respective separation profiles in a batch trap separation cell. Different choke pressures, velocities, orifice sizes, and temperatures were set in order to find the phase-inversion zone and observe how the separation profile is affected by these variables. Bulk flow kinetic energy and water cut, are plotted against the pressure drop in the orifice plate to find the inversion point; comparisons between Differential Dielectric Sensor (DDS) results and available models were made; results indicate a good agreement between the methods used to find where phase inversion occurs. An image processing technique is used to measure the coalescing and sedimenting profiles with respect to time. The Jeelani and Hartland (1998) model predictions for


crude oil tests were compared with the experimental results finding good agreement between each other. An uncertainty analysis of the crude oil tests and the Jeelani and Hartland (1998) model predictions for these tests was carried out, finding that the model can be used to predict the separation profiles for crude oil testing.

Ongoing Projects (7-18)

7) Falling Film and Gas Entrainment in a Tall GLCC© (TUSTP)

The objective of this project is to acquire local experimental data on falling film in a tall GLCC ©

and the associated gas entrainment and gas carry-under (GCU) for air-water and air-oil cases. A mechanistic model and a design code have been developed for the prediction of fraction of gas carried downward in the tall GLCC©. A new facility is constructed to enable the local measurement of the falling film at several locations along the GLCC©. New state-of-the-art instrumentation, namely, Wire Mesh Sensor (WMS) and Film Measurement Sensor (FMS), have been used to acquire data on the falling film and gas entrainment region, respectively. The developed model is divided into 3 sub-models, as follows: (1) falling film analysis including thickness and velocity and the terminal flow conditions; (2) “wall-jet” gas entrainment process; and, (3) bubble disengagement region and fraction of gas carried downward in the liquid column.

8) Multiphase Flow in Downcomers (TU-CoRE)

Downcomers are important conduits for multiphase flow from offshore platforms to seabed. Unfortunately, the uncertainty in the predictions of pressure loss of multiphase flow between platforms is often dominated by the uncertainty in holdup and pressure drop in the downcomer. One of the important features of downward multiphase flow that is not predicted well is the transition between annular falling film and dispersed bubble flow patterns along the downcomer. The location of the transition to dispersed bubble is very important as the large change in liquid holdup produces a large change in the hydrostatic head, which could have a dramatic effect on the total pressure loss in the pipeline. In this project, experimental data will be acquired on the transition between annular falling film and dispersed bubble flow, and the associated gas entrainment. In an ongoing TUSTP project, models have been developed for falling film and associated gas entrainment and gas carry-under in a tall GLCC. Using this modeling approach, it is possible to predict the location of the transition between flow patterns for various rates, and improve the pressure loss predictions for pipeline systems with downcomers. Currently the facility can handle liquid flow rate upto 92 gpm. Potential future facility modifications will enable handling higher liquid flow rates and investigate the instabilities of the falling film that could cause wave breakup and generation of significant amount of falling droplets.


9) Droplet Coalescence and Deposition in Curved Pipes (TU-CoRE-I/UCRC)

Flow conditioning devices are widely used at the inlet to improve the performance of wet gas separators. Simple geometries such as 1800 pipe bend or two 900 elbows section can work as coalescers at low cost and without pipeline modification. Better understanding of coalescers makes it possible to optimize their design and applications. A facility has been designed consisting of two main test sections: a fixed straight pipe and an exchangeable curved pipe sections with the same length. The curved pipes are 1800 pipe bend or two 6D radii elbows configuration, which can be tilted from 00 to –100. Experiments have been carried out using water and air flow with superficial gas velocities of vSG=20 to 45 m/s, and superficial liquid velocities of vSL=1.4 to 6.3 cm/s. The droplet deposition fractions (DDF) were measured in the horizontal straight pipe section, and in the curved pipe sections in both horizontal and downward inclined configurations (inclination angles of -50 and -100). It was found out that higher DDF occurs in the curved pipes, as compared to the straight pipe section. Similar DDF values were measured for the 1800 pipe bend or 6D radii elbows configurations. Also, the inclination angle has a minor effect on the DDF in the curved pipe. It can be concluded that that it is sufficient to use horizontal long elbows configuration for droplet deposition. Currently, experiments are conducted with new pipe bend consisting of cushion tees and target tees, instead of the elbows. The results will be compared with the previous pipe bend tested. Also, CFD simulations are conducted to shed more light on the flow behavior in annular flow, as occurring in the horizontal pipe upstream of the bend. Simulation will also be conducted for the curved bends for better understanding of the physical phenomena. This will lead to improved mechanistic models for designing coalescing bends. Future research directions include improved instrumentation for film thickness and liquid entrainment measurements and modified experimental apparatus to enable the conduct of tests at high liquid flow rates.

10) A Foam Breakup in Cyclones – Foam Characterization Rig (FCR) (TU-CoRE)

Foam generation, characterization and breakup have been of great interest to production operations in the industry. Foam can be broken out utilizing chemical, thermal and mechanical methods. Chemical and thermal processes are expensive and cause damage to the produced oil. Mechanical methods, such as cyclonic separators, can be used to break foam in a cost efficient manner. In off-shore operations where there are weight and space limitations, cyclonic devices can be efficiently employed, owing to their small footprints. The current foam study is carried out utilizing the Foam Characterization Rig (FCR), consisting of a 1” pipe loop, in order to generate and flow the foam into a 2” inlet cyclone or a 2” GLCC for breakup and separation. The objective of this project is to determine which configuration provides a better breakup efficiency performance under different flow conditions. Also, the effect of increasing surfactant concentration on the cyclone performance is studied. A foam batch model for foam decay prediction will be developed and tested against the acquired data. This model will be extended to swirling flow in a cyclone, operating under increased “g” forces. The developed model will be tested against the acquired experimental data and refined as necessary. A design code and design criteria, based on the developed model will be delivered to the supporting industry.

11) Gas Effect on Differential Dielectric Sensor (DDS) Measurements (TUSTP)


The oil and gas industry deals with some of the most challenging metering applications. One of these is the measurement of percent water in crude oil production streams (water-cut) at the point of allocation. The use of microwave permittivity has been shown to be very effective as a multiphase metering principle. Differential dielectric sensors (DDS©) have been developed by Chevron for water-cut measurement. The objective of this research is to study the performance of the DDS under three-phase flow conditions to determine the impact of the presence of gas in the liquid stream. The approach for this study will be to keep all conditions unchanged as the gas volume fraction (GVF) is increased. For this study a Micromotion multiphase flow meter will be used as a reference, therefore an uncertainty analysis of both the DDS and the Micromotion will be carried out. The scope of this project includes the development of a model for the gas effect on the DDS and acquisition of data using our state-of-the-art experimental facility.

12) Fluid Shear Effects of Production Equipment (TU-CoRE)

The objectives of this project is to investigate the effect of shear imparted on oil-water flow by production equipment, such as pumps, chokes, valves and pipe fittings. Both experimental data acquisition and modeling will be conducted. The developed models are to be used in flow assurance simulations to represent shear causing components. This will reduce the uncertainty in current simulations for subsea systems. A methodology for characterizing fluid shear effects will be developed, which can be deployed in the field. Droplet size distribution and flow rheology and separation time will also be studied. The research tasks are as follows: (i) Review of available droplet size measurement techniques; (ii) Conduct shearing experiments with oil- water flow testing centrifugal pump and positive displacement pump; (iii) Collect variety of field tests data and construct a data bank; and, (iv) Compare experimental data with breakup and coalescence model of Avila (2006) and Rheology model of Vielma (2006). The first phase of this project has been completed on dilute flow in centrifugal pump (Phase I) for low concentrations (100-200 ppm) measuring droplet size distributions in both inlet and outlet of pump, utilizing the Jorin device. As part of Phase II, dense oil in water-continuous flow in centrifugal pump, the OPUS device of SYMPATEC has been successfully tested in TUSTP loop and been used for the experimental program of this phase. The water cut was changed between 75, 50 and 25%. In Phase III, namely, dense water in oil-continuous flow, a laser diffraction based instrument has been successfully utilized in the experimental program with different flow rates and pump speeds. The water cut varied between 10, 25, 40%. Modeling studies to predict mean droplet size and minimum droplet size will be conducted. A methodology for characterizing fluid shear effects of centrifugal pump will be developed, which can be deployed in the field.

13) A Study of Interfacial Phenomenon of Crude Oil & Water Dispersions using the DCR (TU-CoRE)

Four studies have been completed by TUSTP on the effects of several parameters on the separation process in the DCR batch separator, including temperature, pressures, water-cut, fluid properties and shear effect of restrictions. The present work focuses on the following areas: (1) Conducting experiments with crude oil for different orifice plate sizes (β=0.3 and β=0.5), flowing velocities (0.89 and 1.71 ft/s) salt concentrations (0%, 3.5%, and 18%), and water cuts (25%, 50% and 75%). (2) Evaluate the behavior of crude oil using in-house model fluids and develop a methodology for characterizing crude oil-water dispersions. (3) Evaluate the effect of salinity on crude oil-water dispersion separation by carrying out experiment with mineral oil and brine. Comparison of data acquired with mineral oil and with crude oil will be carried out. (4) Evaluate


the effect of demulsifiers formed with crude oil to evaluate the stabilizing effect of naturally occurring surfactants in crude oil (especially asphaltenes). The deliverable of this project will be experimental data and further modeling of interfacial phenomenon for the characterization of crude oil-water dispersions.

14) Multiphase Flow Splitting in Looped Pipelines Utilizing Different Splitting Tees (TU-CoRE)

Parallel/looped multiphase flow pipelines are utilized by the industry in order to reduce pressure drop and increase capacity. However, no fundamental understanding of the flow behavior and no predictive methods are available for such systems. The scope of this project is twofold: (1) to investigate gas-liquid splitting in parallel pipelines, utilizing interchangeable vertical and horizontal splitting tees. A vertical plate is installed in the horizontal tee along the vertical diameter. A state-of-the art facility will be used to run experiments and investigate if these 2 tee configurations will promote equal GLR in the looped lines. This will make the operation of downstream separation facilities more efficient. (2) Develop a model for predicting gas-liquid splitting flow in looped lines, based on energy (pressure drop) minimization. Initial data acquired with the 2 splitting tees show that no improvement in equalizing GOR in the 2 looped lines is achieved, as compared to the simple horizontal splitting tee. Also, a splitting model based on energy minimization for homogeneous flow has been developed. This model will be tested against experimental data and extended to flow pattern dependent model.

15) Simulation of Different Geometries of the Differential Dielectric Sensor (DDS©) (TUSTP)

In oil and gas industry, multiphase measurement technologies will be very important; one of these is the measurement of the permittivity in pure water, sea water and oil. TUSTP has developed a rectangular model for Differential Dielectric Sensor (DDS) for water-cut and permittivity measurement. Unfortunately, if one of the parameters such as geometry and material properties changed, the whole development process of the model has to be repeated. The objective of this project is to use software named High Frequency Structure Simulator (HFSS) by Ansoft Company to create, simulate and calculate the permittivity of different sensor fluids. HFSS is one of the most popular and powerful application software in electromagnetic field. The status of the present work is: (1) a comprehensive literature review has been finished leading to the following conclusions: most of the published studies are about different models measuring the complex dielectric constant (permittivity) for pure water, sea water and oil. In accordance with the frequency, temperature and salinity, the models will be divided into several categories. (2) Create the rectangular DDS model using the HFSS software, and use the simulation results to calculate the real and imaginary parts of data in Matlab, finally calculate the permittivity. (3) Benchmark the model with results of the existing experimental data from rectangular DDS. (4) Investigate the sensitivity of different sensor geometries in HFSS software and develop protocol for sensor optimization for a given application.

16) Oil Chemistry in Emulsion Characterization (TU-CoRE)


Separation of the produced oil-water dispersions is an important issue, both in terms of the environmental regulations and the operational/technical difficulties involved in handling these dispersions, before the crude oil are sent to the downstream processing plants. To date, oil-water separation process is mostly an art, but, not a science as there are numerous factors which influence the dispersion characteristics. Keeping this important aspect in mind, TU-CoRE has commenced different projects to study the effects of various important parameters such as pressure, temperature, water cut, and shear on the separation profiles of oil-water dispersions. For all the above studies a state-of-the- art Dispersion Characterization Rig (DCR) has been used. However, whatever is the cause for the production of the oil-water dispersions, separation process involves different physiochemical processes of which droplet-droplet and droplet-interface coalescence rate and time are the most important factors and many times they are the main controlling parameters. The objective of this work is to experimentally measure the coalescence time using a simple custom made experimental setup and generate the separation profiles of the fluid system at the same experimental conditions in the DCR. Finally, different batch separation models will be tested to correlate the results from coalescence time measurement and the corresponding separation profiles obtained using the DCR. Successful correlation would allow one to predict the separation time of a given oil-water system, in a separator, only by measuring coalescence time.

17) High Pressure Entrainment Measurement and Modeling (TUSTP/SwRI)

Wet gas scenarios are encountered during natural gas production, transmission, and processing. The liquid entrained in the gas refers to the fraction of the liquid phase suspended and transported in the gas phase in the form of droplets. The liquid entrainment plays an important role in the design and operation of flow transmission lines, the design of gas processing and separation equipment, and corrosion occurrence and mitigation inside the pipe. The motivation of this study is to expand the predictive capabilities of liquid entrainment in gas by incorporating the effect of high pressures that can be encountered in the field. This study involves an experimental program for measuring the liquid entrainment in gas at high pressure conditions, developing or improving modeling capabilities for the prediction of entrainment, and validation of the model using experimental data. To date a number of experiments have been conducted at pressures of up to 1,000 psig, using nitrogen for the gas phase and water or oil for the liquid phase. A number of models and correlations for liquid entrainment have been identified and will be enhanced by benchmarking with available data. New experimental techniques are being developed for future experiments.

18) Sand Transport in Multiphase Pipelines (TUSTP)

Most of the published sand transport studies have been conducted under either single-phase liquid or single-phase gas with solids. Few experiments have been reported for multiphase gas-liquid-solid flow in pipes. The complexity of the sand transport mechanisms and the multiphase flow behavior have hindered understanding and development of design tools for such phenomena. The objective of this project is to predict the critical flow rates that will result in sand deposition or the transport of a sand bed. A comprehensive literature review is being conducted in order to gain better understanding of the flow behavior. A state-of the art sand transport facility with liquid-gas-solid separation capability has been designed and constructed. Preliminary experiments are


underway. Models will be developed for predicting the critical flow rates ensuring either sand deposition or sand bed shear initiation. The models will be tested against the acquired experimental data and refined as necessary. Potential future direction is the investigation of sand deposition in short near-horizontal pipe separators. The length of turbulence decay region, particle trajectory length, effects of g/o/w interfaces, and effect of particle characteristics, e.g., size, density, shape, wettability and compound wettability will be investigated.

Proposed Future Projects (19-27)

19) Field Testing of LLCC© (Future)

Most of the over 4500 field compact separators are GLCC©s or GLCC systems. The GLCC© has been tested in field laboratories in Humble, Houston (closed) and CEESI, Colorado flow loops. However, no testing and deployment of individual LLCC© separators has been carried out. Limited testing of the LLCC© has been conducted as part of a CMSS©. TUSTP members have shown interest in testing the LLCC© in the field. In this project, a field LLCC© separator will be fabricated, installed in a field and tested in collaboration with independent producers. Experimental data will be acquired on the LLCC© performance and efficiency under water continuous flow conditions. The data will be used to benchmark the LLCC© code of TUSTP and refine it as necessary.

20) Separation of Slurries in GLCC© Compact Separators (Future)

This project is an extension of the completed gas-liquid-solid GLSC separator study for air drilling systems (OCAST). The air drilling application requires a gas-solid-liquid separator capable of handling low concentration of solids in liquid resulting from the injection of liquid into the air-dust mixture stream. However, mud drilling applications require the capability to handle high solid concentrated liquid slurry mixed with gas. The objective of this project is the development of a novel compact separation system for gas-liquid-solid separation for managed pressure drilling cuttings/mud separation applications. This can be achieved by modifying existing compact cyclonic separators for gas-liquid flow (as developed by The University of Tulsa) to concentrate the drilled solid particles into a solid rich stream for efficient separation. The developed compact separation system should also accommodate and control possible gas kicks during the drilling operation. It can also be used for sand removal from oil/gas production streams. The deliverables of this investigation are: (1) Experimental results of laboratory testing of the 3-phase gas-liquid-solid compact separator for mud drilling operation; (2) Field data of 3-phase gas-liquid-solid compact separator prototype; and, (3) An improved design and design criteria of 3-phase gas-liquid-solid compact separator ready for field applications.

21) Platform to Platform Pipeline Flow Behavior (Future)

There is a great uncertainty in the predictions of pressure loss in gas-liquid flows between platforms. Several flow patterns can occur, including severe slugging and ultra severe slugging.


The system can also be dominated by the flow through the downcomer, where transition between annular falling film and dispersed bubble flow occurs. The location of the interface, which is not known, can significantly affect the pressure recovery in the downcomer. The objective of this project is to construct a “platform to platform” flow system on a skid. This system will be used for both demonstration and research. Experimental data will be acquired for the different flow patterns and a mechanistic model will be developed for prediction and design purposes. The final deliverable is a design code for “platform to platform” systems.

22) CFD Simulations of CMSS© Components (Future)

Appropriate CFD simulations will be carried out to better understand the flow behavior of specific regions of the compact separation systems, such as entry region of horizontal pipe separator, slug damper, helical pipe, etc. CFD simulations will also be conducted to augment the experimental investigations by simulating different flow conditions such as high viscosity, high surface tension, etc.

Revised and improved CFD simulations for the compact separation components, namely, the LLCC©, HPS© and LLHC and for flow conditioning devices, namely, the Helical Pipe (HP) and Slug damper (SD©) will be conducted. The simulations will incorporate the physical phenomena occurring in the separators. The input variables will include the operational parameters (oil and water flow rates, pressure and temperature), geometrical parameters (separator configuration) and PVT properties. The output variables will include the hydrodynamic flow behavior in the separator, the pressure drop and the global separation efficiency. The CFD simulations are essential for the development of the design codes for the different units and the CMSS©.

23) Operational Envelope for LCO in GLCC© – Experiments and Modeling (Future)

The models for the prediction of the operational envelope (OPEN) for liquid carry-over (LCO) and the corresponding prediction of percent LCO in the GLCC© design code need modifications. An experimental program will be conducted and data will be acquired for the OPEN under different flow conditions. A new model for the OPEN will be developed from first principles and implemented in the GLCC© design code.

24) Gas Carry-Under in GLCC© – Experiments and Modeling (Future)

The models for the prediction of the gas carry-under (GCU) and the corresponding prediction of percent GCU in the GLCC© design code need significant improvements especially as they do not show the sensitivity to fluid properties such as viscosity and surface tension as observed in the field data. An experimental program will be conducted and data will be acquired for GCU under different flow conditions. A new and improved model for the GCU will be developed and implemented in the GLCC design code and validated with the experimental data.

25) GLCC© Inlet Slot Optimization (Future)


The inlet nozzle/slot geometry has not been closely investigation in the past, including the slot opening cross sectional area and the nozzle plate orientation (vertical or off vertical). Also the -270 inclination angle of the inlet has been optimized for conditions of equal GLCC © and inlet diameters. For GLCC©s where the inlet diameter is smaller than the GLCC© diameter, the optimal inlet inclination angle might be lower than -270. An experimental and theoretical investigation will be carried out aimed at optimizing the inlet design.

26) GLCC© Liquid Outlet and Gas Outlet Optimization (Future)

This project is focused on the optimization of the GLCC© liquid outlet and gas outlet geometries. Axial, radial and tangential outlets will be investigated experimentally and modeled theoretically, which will result in proper design of the outlets.

27) Verification of GLCC© Performance with Real Fluids at High Pressure (Future)

The long term scope of this multi-year project is as follows:

Performance tests with high pressure (HP) (20 - 100 bar) Performance tests with real fluids (condensate and crude oil) Performance tests at high gas and liquid loads Evaluation of existing models with data from test with HP and real fluids Extension of GLCC© model for HP and real fluids Field testing of GLCC©

Verification of model with field data

28) A Review of GLCC© in Topsides and Subsea Processes (Future)

The objective is to conduct a comprehensive assessment of GLCC© separator as part of the production process chain, beyond testing or metering applications. The review will:

- Identify the demonstrated/proven capabilities of GLCC© in these process functions- Establish the gaps and outline a technology development and/or qualification path

The long term scope of this multi-year project will involve as follows:

Review the known relevant applications topside/subsea Categorize those applications in terms of use or position in the separation chain Map the domain of qualification in terms of

Pressure Temperature Viscosity Rates GOR Presence of slugging? Sand? Foam? Additives? Sensitivity to fast/slow variations of main parameters Control strategies

Assess the demonstrated performance in the ‘qualified’ domain (compare to predictions / expectations and compare the effective operating range to the design range)


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